Trying ot convert a C# to connect to CPP. Facing below exception where it does not show detailed error.

Syntax Error At Input(1). Below is my CPP Header File. Error occurs at the code System Serializable

#pragma once
#pragma warning( disable : 4950)
namespace Employee {
    namespace Error {

        [System::Serializable] // Error Occurs Here
            public ref class EmpException : public System::ApplicationException
        {
        public:
            EmpException();
            EmpException(System::Int32 errorCode);
            EmpException(System::String^ message);
            EmpException(System::Int32 errorCode, System::String^ message);
            EmpException(System::String^ message, System::Exception^ innerException);
            EmpException(System::Int32 errorCode, System::String^ message, System::Exception^ innerException);

            virtual ~EmpException();

            virtual property System::Int32 ErrorCode {
                System::Int32 get() {
                    return m_errorCode;
                }
            }
    }
}

Below is my Swig Interface File

%module testWrapper

%include <std_common.i>
%include <typemaps.i>
%include <std_string.i>
%include <std_wstring.i>
%include <std_vector.i>
%include <std_map.i>
%include <std_pair.i>
%include <windows.i>

using namespace std;


#define unix


%{
     #include <empexcption.h>
 %}
 %include "empexcption.h"